Fan casing



June 24, 1941 F. L. PIERCE FAN CAS ING Filed July 11, 1958 2 Sheets-Sheet 1 I NV ENTO R FrankLPieree ATTORNEY June 24, 1941.. L, PIERCE 1 2,246,859

FAN CASING Filed July 11, 1938 v 2 sheets-sheet 2 :7 6 fizz/ML Pierce ATTORN EY Patented June 24, 1941 FAN CASINfr Frank L. Pierce, North Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio, a

corporation of Ohio Application July ll, 1938, Serial No. 213,519

3 Claims.

This invention relates to suction cleaners, and more particularly to fan casings adapted for use in suction cleaners.

In using suction cleaners, considerable sand and small particles of solid material is removed from the surface being cleaned and is drawn into the fan casing subjecting the walls of the latter to a terrific sand blasting which wears the walls of the fan casing and necessitates replacement of the latter at considerable expense. It has been suggested to rivet or bolt a liner in the fan casing but this type of construction is expensive and open to other and further objections in that the joints between the liner and fan casing walls and the rivets, provide ideal spots for the collection of dirt and pins and other articles which break up the smooth surface desired along the scroll of the fan casing and clogs the latter.

It is therefore an object of the present invention to provide a fan casing having a liner formed integral therewith to provide a smooth surface along the inner walls of the fan casing. Another object is to provide a fan casing liner to add additional wear resisting material at the areas most subject to sand blasting. A further object is to providea suction cleaner main casing and fan casing molded around a fan casing liner. Another object is to provide a fan casing having a liner provided with a reinforcing strip, the latter extending throughout the wall thickness of the fan casing. A further object is to provide a method of die-casting or molding a fan casing directly around a stamped metal fan casing liner, Another object is to provide a stamped metal fan casing liner having means to position the latter while die-casting or molding the fan casing around the liner, the positioning means also anchoring the liner to the molded fan casing. Still further objects and advantages of the invention will be apparent from the specification and drawings; wherein:

Figure 1 is a broken perspective view of a suction cleaner main casing, fan casing and liner;

Figure 2 is a perspective view of the stamped metal liner prior to molding the fan casing around the same;

Figure 3 is a bottom plan view of a suction cleaner partly broken away to illustrate the fan casing and main casing construction;

Figure 4 is a section along the line 44 of Figure 3;

Figure 5 is a section along the line 5-5 of Figure 3, and

Figure 6 is a section along the line '65 of Figure 3.

The embodiment of the invention herein disclosed comprises a suction cleaner having a main casing It provided with a nozzle II and a top wall H from which depends side walls or skirts l3. Cast integrally with the main casing I0 is a fan casing l4 defining a fan chamber l5 provided with a fan chamber inlet I6 and a tangential discharge conduit H which exhausts into a filter bag It removably secured to the cleaner casing It by a pair of nut and bolt connections The nozzle is provided with front and rear lips 2i] and 2| respectively, and extending rearwardly from the opposite ends of the rear nozzle lip 2| is a pair of members 22, 22 which depend integrally from the top wall l2 of the main casing and the bottom wall of the fan casing M to provide an air passageway 23 from the nozzle II to the fan chamber I5. Rotatably mounted in the nozzle I l is an agitator 24 provided with an annular groove 25 receiving a belt 26 extending to a drive pulley 21 carried by the armature shaft of an unshown motor adapted to be supported on the main casing I0 above the fan chamber l5. Carried by the motor armature shaft and disposed in the fan chamber I5 is a centrifugal fan 23 provided with a fan back 29 and blades 30. The cleaner is supported on front and rear wheels 3! and 32 respectively, and is manipulated by a handle having its bail 33 pivotally connected at 3 to the cleaner casing I0.

The fan casing I4 comprises an 'arcuate side wall 35 depending integrally from the top wall I2 of the main casing, and an integral bottom wall 36 provided with the fan chamber inlet l6 which is concentric with the motor armature shaft, the bottom wall 36 cooperating with the integral side walls 35 and the top wall 12 of the main casing to form the tangential discharge conduit 11 communicating with the fan chamber and the filter bag l8. The top wall of the fan chamber is formed by the bottom plate of the unshown motor which rests on the top wall l2 of the main casing Ill. The fan casing I4 is molded around a stamped steel fan casing liner 40, shown in Figure 2, which is provided with a major bottom wall 4| and a major side wall 42 part of the latter being arcuate as indicated at 43 and terminating at one end in a tangential side wall 44 and at the opposite end in a reversely bent lip 45. A reinforcing strip of metal 46 is welded to the outer surface of the liner side wall 42 and forms a minor wall of the fan casing liner 40 where the fan casing is subjected to the most severe sand blasting. A plurality of positioning lugs 41 are welded to the side wall 42 of the liner, and annularly arranged spaced positioning lugs 48 are welded to the outer surface of the bottom wall 4| of the liner. These lugs along with the reinforcing strip 46 serve to position the liner 40 in the mold while the main casing I and the fan casing I4 are cast around the liner 4B. Spaced annularly around the outer surface of the fan casing side wall 35 are molded ribs 52 each of which provide a bridge of metal or other type of well-known molding material across that portion of the fan casing side wall 35 which is severed by the reinforcing strip 46 of the fan cas ing liner, to thereby insure a substantial tie between the upper and lower portions of the fan casing.

Referring to Figures 1, 4 and it will be seen that the inner periphery 50 of the fan liner bottom wall 4i lies flush with the fan casing bottom wall 36 and is spaced from the fan chamber inlet it. The liner side Wall 42 extends substantially throughout [the height of the fan casing side wall 35 and its periphery 53 is flush with the same, while the ends 45 and 44 of the liner side wall are flush with the vertical surface of the discharge conduit, as shown in Figure 3. Referring to Figure 1 it will be seen that the reinforcing strip 45 together with the liner side wall 42 extend throughout the wall thickness of the fan casing side wall 35. Accordingly no open joints are present between the liner and fan casing walls and the danger of dirt accumulating in the fan chamber is eliminated, and the thickened portion 45 is provided in the fan liner where the fan casing is subjected to the most severe sand blasting.

In operation, the motor rotates the fan 28 to create suction which draws in dirt-laden air from the floor covering being cleaned through the nozzle ll, air passageway 23, the fan chamber inlet l5, and discharges the dirt-laden air onto the scroll of the fan casing 14 and then through the exhaust ll intothe filter bag !8, as indicated in Figure 3. The dirt-laden air strikes the walls of the fan casing with considerable force and tends to wear away the fan casing. However, the liner 40 provides a surface which resists wear from impact with the dirt-laden air. At that area where the wear is greatest the reinforcing strip 46 is provided and in combination with the liner side wall 42 provides a wear resisting liner that extends throughout the wall thickness of the fan casing to withstand the impact of the dirt in the dirtladen air. Since the fan casing is molded around the liner 48 no grooves are present in the fan casing and accordingly the dirt cannot collect in the fan chamber to clog the latter or decrease the efficiency of the same.

In order to make this embodiment of the invention, the fan casing liner is stamped from sheet steel and the reinforcing strip 46 and the positioning lugs 41 and 48 are welded thereto and the liner is then formed to the contour shown in Figure 2, which corresponds with the outline of the molded fan casing. The liner 40 is then inserted in a half of a die or mold, the positioning lugs 41, 48 and the reinforcing strip 46 holding the stamping in the proper position in the mold. Upon closing the die or mold the positioning lugs lie against one side of the die or mold and the stamping is held firmly While any molding material well known in the prior art, such as metals or plastics is cast to form the main casing I0 and fan casing l4 integrally and around the fan casing liner 40.

From the foregoing it will be perceived that the main casing and fan casing are molded as a unit and around the stamped steel liner to provide an integral structure; that the peripheral edges and 53 of the liner are flush with the scroll surface of the fan casing; that no grooves are formed between the liner and fan casing whereby the danger of dirt, pins and so forth, collecting in the fan chamber and clogging of the latter is eliminated; and that the liner extends throughout the side wall thickness of the fan casing Where the latter is subjected to the most severe sand blasting.

I claim:

1. A fan casing having side and bottom walls defining a fan chamber for a fan adapted to expel dirt laden air therefrom, and a fan easing liner disposed along portions of the inner surfaces of said fan casing walls, said fan casing liner having a thickened portion extending from its inner surface inwardly of said fan casing walls to provide additional thickness for resisting wear from the dirt circulated by the fan and impacting against said fan casing liner.

2. A fan casing having side and b ottom walls defining a fan chamber for a fan adapted to expel dirt laden air therefrom, a fan casing liner disposed along portions of the inner surfaces of said fan casing walls, said fan casing liner having a thickened portion extending from its inner surface inwardly of said fan casing walls to provide additional thickness for resisting wear from the dirt circulated by the fan and impacting against said fan casing liner, said thickened portion of said liner extending throughout the wall thickness of one of said fan casing Walls.

3. A fan casing having a wall defining a fan chamber, a fan casing liner having major and minor wall portions, said major Wall portion lying flush with the inner surface of said fan casing wall, and said minor wall portion being spaced from marginal edges of said major wall ancll projecting therefrom into said fan casing wa l.

FRANK L. PIERCE. 

